Evaluation of Arctic Multibeam Sonar Data Quality using Nadir Crossover Error Analysis and Compilation of a Full-Resolution Data Product

Ashton F. Flinders, Larry A. Mayer, Brian A. Calder, Andrew A. Armstrong

Center for Coastal and Ocean Mapping - Joint Hydrographic Center University of New Hampshire Durham, NH 03824, USA.

Corresponding Author: Ashton F. Flinders, [email protected]

Abstract

We document a new high-resolution multibeam bathymetry compilation for the Canada Basin and Chukchi Borderland in the Arctic Ocean–United States Arctic Multibeam Compilation (USAMBC Version 1.0). The compilation preserves the highest native resolution of the bathymetric data, allowing for more detailed interpretation of seafloor morphology than has been previously possible. The compilation was created from multibeam bathymetry data available through openly accessible government and academic repositories. Much of the new data was collected during dedicated mapping cruises in support of the United States e�ort to map extended continental shelf regions beyond the 200 nm Exclusive Economic Zone. Data quality was evaluated using nadirbeam crossover-error statistics, making it possible to assess the precision of multibeam depth soundings collected from a wide range of vessels and sonar systems. Data were compiled into a single high-resolution grid through a vertical stacking method, preserving the highest quality data source in any specific grid cell. The crossover-error analysis and method of data compilation can be applied to other multi-source multibeam datasets, and is particularly useful for government agencies targeting extended continental shelf regions but with limited hydrographic capabilities. Both the gridded compilation and an easily-distributed PDF map are freely available through the University of New Hampshire’s Center for Coastal and Ocean Mapping (ccom.unh.edu/theme/law-sea). The pdf is a full resolution, small file-size product that supports interpretation of Arctic seafloor morphology without the need for specialized gridding/visualization software.

Keywords: Arctic Ocean, Canada Basin, Chukchi, crossover analysis, multibeam, ECS

Readme:

The included Github files give a working example of how to use the Generic Mapping Tools (GMT) x2sys subroutine to calculate the crossing errors for a set of extracted multibeam nadir lines.

Github Files:

Make the proper directory structure, prior to running example script;
    x2sys_makedir.bash

Main example script (performs the crossover analysis);
    x2sys_example.bash

Example lines;
    Healy_HLY0602_1_NADIR.xyzt
    Healy_HLY0602_2_NADIR.xyzt
    Healy_HLY0602_3_NADIR.xyzt
    Healy_HLY0602_4_NADIR.xyzt
    Healy_HLY0602_5_NADIR.xyzt